(1) Field of the Invention
The present invention generally relates to the field of rotary driven blades, and devices making it easier and faster to change blades. More particularly, this invention relates to a carrier fastened to the motor-driven rotary drive shaft of a machine, such as a lawn mower; the carrier holds the blade in a manner that is secure in the locked configuration, but which can readily unlocked for removal of the blade and replaced with another blade.
(2) Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98.
Although carriers for blades are generally known in the field, such carriers are usually for reciprocating saws and other similar devices, and such carriers typically address only the blade-changing aspect without addressing the need to do with a device having both strength and durability while also being easily operated by somebody without requiring specialized tools, training, strength or an inordinate amount of time.
U.S. Pat. No. 3,877,146 issued to Pittinger discloses a blade holder having a blade with a central circular hole, a hub or cylindrical body, a blade locating means, and elastically deformable projections or fingers securely holding the blade; the blade may be released by pivoting it about the blade locating means on the holder. The holder is connected with the drive shaft, and holds the blade for rotation. The retaining fingers are formed integrally with the holder. As the blade is rotated from the assembly position, the opposite half-sections of the blade slide under the retaining fingers until they abut near the main body of the holder. As the blade is turned to the locking position, a slight torque must be applied to force it under the raised area by slightly deforming the retaining fingers. Each raised area acts as a detent mechanism.
U.S. Pat. No. 2,875,569 issued to Sauer discloses a blade mounting device for a lawn mower having a drive shaft that rotates a flexible blade, the device having the blade flexibly attached by a spring to a face plate having a blade supporting structure that is secured to the drive shaft. The blade includes a protrusion that is engageable with the wall portion of the face plate. When the blade is assembled to the face plate, the headed screw extends through the cap, the coil spring, the blade and the face plate, and is threaded coaxially into the end of the shaft with the coil spring between the blade and the head of the screw. The spring normally holds the blade against the face plate to keep the protrusions in the recesses or holes in the face plate and against the wall portion of the face plate.
U.S. Pat. No. 4,586,257 issued to Rittenhouse discloses a blade holder including a holder body connected to a rotary drive shaft. The holder body has a wide and flat outer (lower) face upon which the specialized blade is secured between tabs. The blade essentially slides into two guide grooves along the side edges of the flat outer face, held in place by lip tabs. A central engaging means engages a circular central hole in the blade. The engaging means includes an engaging pin, and a compression spring which biases the engaging pin outward (downward) from the flat outer face and through the blade hole. The blade can be easily removed from the holder by pressing the engaging pin (which is exposed on the bottom of the device) inward against the compression spring and sliding the blade until tabs are between lip tabs, so that the blade can be lifted away from the holder.
None of the aforementioned references discloses: (a) a housing having a bottom and a false floor and a sidewall slot-opening forming a channel therebetween holding the blade; and (b) a housed disk having a tip downstanding from its floor, and (c) a housed compression spring biasing the blade-engaging tip through an opening in the housing's false floor and through a center hole in the blade to lock it within the channel.